Clustering and descendants of MUSYC galaxies at z < 1.5

N. D. Padilla, D. Christlein, Eric Gawiser, R. E. González, L. Guaita, L. Infante

Research output: Contribution to journalArticle

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We measure the evolution of galaxy clustering out to a redshift of z 1.5 using data from two Multi-wavelength Survey by Yale-Chile (MUSYC) fields, the Extended Hubble Deep Field-South (EHDF-S) and the Extended Chandra Deep Field-South (ECDF-S). We use photometric redshift information to calculate the projected-angular correlation function, ω(σfrom which we infer the projected correlation function Ξ(σ). We demonstrate that this technique delivers accurate measurements of clustering even when large redshift measurement errors affect the data. To this aim we use two mock MUSYC fields extracted from a Λ-cold dark matter (ΛCDM) simulation populated with galform semi-analytic galaxies which allow us to assess the degree of accuracy of our estimates of Ξ(σ) and to identify and correct for systematic effects in our measurements. We study the evolution of clustering for volume limited subsamples of galaxies selected using their photometric redshifts and rest-frame r-band absolute magnitudes. We find that the real-space correlation length r0 of bright galaxies, Mr < -21 (rest-frame) can be accurately recovered out to z 1.5, particularly for ECDF-S given its near-infrared photometric coverage. For these samples, the correlation length is consistent with a constant value of r0= (2.6 ± 0.3) h-1 Mpc for the ECDF-S field, and r0= (3.0 ± 0.4) h-1 Mpc for the EHDF-S field from a median redshift zmed= 0.37 to zmed= 1.15. There is mild evidence for a luminosity-dependent clustering in both fields at the low-redshift samples (up to z = 0.57where the correlation length is higher for brighter galaxies by up to 1 Mpc h-1 between median rest-frame r-band absolute magnitudes of -18 to - 21.5. As a result of the photometric redshift measurement, each galaxy is assigned a best-fitting template; we restrict to E and E + 20 per cent Sbc types to construct subsamples of early-type galaxies (ETGs). These ETGs are separated into samples at different redshift intervals so that their passively evolved luminosities (to z= 0) are comparable. Our ETG samples show a strong increase in r0 as the redshift increases, making it unlikely (95 per cent level) that ETGs at median redshift zmed= 1.15 are the direct progenitors of ETGs at zmed= 0.37 with equivalent passively evolved luminosities.

Original languageEnglish (US)
Pages (from-to)184-198
Number of pages15
JournalMonthly Notices of the Royal Astronomical Society
Issue number1
StatePublished - Nov 1 2010


All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


  • Cosmology: observations
  • Galaxies: distances and redshifts
  • Galaxies: statistics
  • Large-scale structure of Universe

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